The No. 1 man in a toilet scam that flushed almost $1 million from the city was sentenced yesterday to three years in the can.

Wiping tears from his eyes, plumbing-company owner Abraham Markowitz, 46, of Brooklyn, pleaded with Manhattan federal Judge Richard Casey to spare him from prison, saying his wife could not raise their mentally retarded 11-year-old son without him. Casey rejected the plea and handed down a 33-month sentence.

The company contracted to administer the scheme, Volt Viewtech, and plumbers like Markowitz claimed they’d installed low-flushing toilets when they hadn’t, the feds charged.